Air-sampling pump using maxon DC motor protects workers' health

Air-sampling pumps are used to collect a dust or vapour sample in a working environment. The Apex2 personal pump is a small, robust appliance that an individual wears on the body. It draws air through a filter, or sorbent tube, where the hazardous substances are deposited. The filters, or tubes, are then processed in a lab to determine the levels. An occupational hygienist will be able to calculate the level of exposure to the individual using data from the pump, such as the flow rate and the volume of air drawn through the filter, or sorbent tube, and the amount of hazardous substance from the lab results. Companies can use this data to ensure their workers are operating within the exposure limits for that particular substance.

Global organisation Casella approached three companies in the UK to supply sample motors for the Apex2 personal sampling pump, maxon motor uk being one of them. All three motors were rigorously tested. The maxon A-max 22 brushed DC motor was chosen due to the high efficiency and low current, in comparison with the others. The efficiency of the motor at a working load means less power is required and, as the pump is battery operated, the battery life is prolonged (>45 hours). This results in extended run time of the product - the pump will run for an entire shift without recharging. The low inductance of maxon motors helps mitigate low spark ignition, so they do not ignite gases or dust, which is vital for some high-risk industries which require their equipment to be intrinsically safe. The maxon motor was customised with an extended shaft and an added front bearing.

Aamir Qureshi, Technical Lead Design Engineer, comments: "We had used maxon DC motors in our previous sampling pumps, so we had confidence in the products from the start. We have always experienced excellent support from maxon. They have improved delivery times, and speeded up the process to help us with our work on hazardous area certification. maxon's added-value service included a strip down and inspection after a set amount of running hours and a comprehensive report was produced. This included photographs of the worn motor components after testing. From this report we are able to estimate how many more running hours were achievable."

As well as personal exposure monitoring in industries such as pharmaceutical, oil and gas, manufacturing and mining, the Apex2 sampling pump is also used for area and environmental monitoring. For instance, it is incorporated into boundary monitoring equipment for construction and demolition sites or open cast mining, to ensure that the surrounding communities are not affected by the dust created from the sites. There are also applications within asbestos clearance for both personal and area monitoring.

For further information about the maxon A-max 22 brushed DC motor please go to www.maxonmotor.co.uk.